The "Conference Bike" is not quite the same thing as a non-stationary bike desk, but it still insane. (Google has some of these.)
*"The ConferenceBike is pedaled by 7 riders sitting in a circle. One person steers while the other 6 pedal (or not) as the bike moves effortlessly along."
... you should probably plan to take the video in the first few minutes. After that it'll probably be a moot point.